Suspended ceiling and lighting system



P 1, 1964 R. A. D. SCHWARTZ ETAL SUSPENDED CEILING AND LIGHTING SYSTEM 4Sheets-Sheet 1 Filed May 25, 1960 INVENTORS Sept. 1, 1964 R. A. D;SCHWARTZ ETAL 3,145,956

suspmmsn CEILING AND LIGHTING SYSTEM 4 Sheets-Sheet 2 Filed May 25, 1960p 1, 1964 R. A. D. SCHWARTZ ETAL 3,146,956

SUSPENDED CEILING'AND LIGHTING SYSTEM 4 Sheets-Sheet 3 Filed May 25,1960 IN V EN TORS ATTORNEY p 1, 1964 R. A. D. SCHWARTZ ETAL 3,146,956

SUSPENDED CEILING AND LIGHTING SYSTEM Filed May 25, 1960 4 Sheets-Sheet4 IN VEN TORS 20.852734 D. 50/11/4272 BY .ST'PI/EA M Zl/VDl/E/M ATTORNEYUnited States Patent F 3,146,956 SUSPENDED CEILING AND LIGHTING SYSTEMRobert A. D. Schwartz, 1081 Annerley Road, Piedmont, Calif., and StephenW. 'Lindheim, 1146 Keeler St, Berkeley, Calif.

Filed May 25, 1960, Ser. No. 31,619 Claims. (Cl. 240-9) This inventionrelates to a ceiling and lighting structure. More particularly itrelates to an integrated ceiling and lighting system which is suspendedas a unit from a permanent ceiling.

This application is a continuation-in-part of the followingapplications: Serial No. 457,844, filed September 23, 1954, entitledCeiling and Lighting Construction, now issued as United States PatentNo. 2,888,113 on May 26, 1959; Serial No. 625,065, filed November 29,1956, entitled Luminous Ceiling Construction, now Patent No. 2,956,150,dated October 11, 1960; and Serial No. 758,262, filed September 2, 1958,entitled Combination Direct and Indirect Lighting Structure, now PatentNo. 3,085,152, dated April 9, 1963.

In modern lighting and ceiling construction it has become a commonpractice to construct an integrated system which provides both a ceilingand a source of illumination. The ceiling may be an acoustical ceilingwith rows of tubular lamps integrated into the ceiling or the ceilingmay be light-transmitting with tubular lamps separated above toilluminate the ceiling as a whole.

In the past the lighting system and the acoustical and/ orlight-transmitting ceiling have been suspended independently from thepermanent ceiling; or else the lighting fixtures have been suspendedfrom the permanent ceiling and a light-transmitting ceiling is suspendedfrom the lighting fixtures. (By permanent ceiling as used herein ismeant the roof of a single story structure; or a permanent ceilinginstalled at the time the building is constructed; or rafters, joists orbeams of a building; or a slab or other structure between floors in amultiple story building; or some other permanent or structural part of abuilding.)

Where independent suspension means are employed there is thedisadvantage, among others, that parts and labor are duplicated. Wherethe ceiling is suspended from the light fixtures, it is diificult tohave access to the wiring system of the lamps because they are locatedabove the ceiling. Also, it may be necessary and diilicult to coordinatethe lamp spacing with the modules or units of the ceiling system. Forexample, parts of a building such as beams, pillars, rafters and ductsmay interfere with the attachment of the ceiling and lighting componentsof a ceiling and lighting system, in such a way that it is diificult tocoordinate these components.

It is an object of the present invention to provide improvements inlighting and ceiling construction.

It is another and particular object of the invention to provide anintegrated ceiling and lighting system which is suspended as a unit fromthe permanent ceiling of a building.

Yet another object is to provide a ceiling and lighting system which issuspended as a unit from a permanent ceiling and in which the wiringsystem for the lights is readily accessible.

A still further object is to provide a unitary, suspended ceiling andlighting system in which the lamp spacing is independent of the ceilingmodule.

The above and other objects will be apparent from the ensuingdescription and the appended claims.

Certain forms of the invention are illustrated in the accompanyingdrawings, in which:

FIGURE 1 is a fragmentary perspective view of a lighting and ceilingsystem suspended from the permanent 3,146,956 Patented Sept. 1, 1964ceiling of a building in accordance with the present invention.

FIG. 1A is a similar View but illustrating a different angulardisposition of the tubular lamps with respect to the longitudinalmembers of the ceiling-panel and tubularlamp supporting framework thanshown in FIG. 1;

FIGURE 2 is a similar view of another embodiment of the invention.

FIGURE 3 is a similar view of a third embodiment of the invention.

FIGURE 4 is a similar view of a fourth embodiment of the invention.

FIGURE 5 is a fragmentary perspective view of a cross channelconstruction employed in certain forms of the present invention toprovide combined conduits for cross wiring for the lighting system.

FIGURE 6 is a fragmentary, perspective exploded view, similar to thatshown in FIGURE 5 but showing a difierent form of the cross wiringconduits.

FIGURE 7 is a fragmentary perspective view of an end closure for thecross wiring conduits of FIGURE 6.

FIGURE 8 is a fragmentary perspective view of yet another form ofceiling and lighting system in accordance with our invention.

FIGURE 9 is a somewhat diagrammatic view showing the manner in which theembodiment of FIGURE 8 0perates as a direct and reflected lightilluminating system.

Referring now to FIGURE 1, a suspended ceiling and lighting system isthere shown and is generally designated by the reference numeral 10. Itcomprises longitudinal members 11 and cross members 12. The longitudinalmembers 11 are in the form of relatively long channels 11a which providea raceway for necessary wiring for the lamps. A cover 13 is provided foreach of the channel members 12. On each side of the channel portion 12are provided vertically aligned guideways 14. A flange 15 projectsoutwardly from the lower edge of each channel portion 12, the twoflanges 15 preferably being coplanar.

Certain other features of the construction of the longitudinal members11 are described hereinafter with reference to FIGURE 6. Furtherdescription, which is unnecessary for present purposes, will be found inour Patent No. 2,888,113.

In the particular embodiment shown in FIGURE 1 the flanges 15 serve tosuspend light shielding and/or acoustical bafiles 16 each of whichcomprises a filler 17 of suitable sound-absorbing material and a coverportion 18 which may be perforated for acoustical purposes. The upperportion of the cover 18 is formed into U-shaped clips 19 for engagingthe flanges 15.

A permanent ceiling is shown at 24 from which the longitudinal members11 are suspended. The suspension means comprises U-shapedhanger members25, eye bolts 26 adjustably fixed thereto and cables 27 which aresecured at their lower ends to the eye portions of the members 26 and attheir upper ends by any suitable means (e.g., the eye screw shown) tothe permanent ceiling 24.

In the particular embodiment of the invention shown in FIGURE 1 theceiling member shown at 24 may be a plaster ceiling, a concrete slab, arafter, a joist or anything else of a structural character or forming apermanent part of the building and to which wires, cables or rods 27 canbe attached.

Secured to the tops of longitudinalmembers 11, as by means of screws 28,are lamp support pedestals 29, each having an upright portion 30, ahorizontal base 31 and a horizontal top portion or platform 33. As willbeseen,

each of the pedestals 29 is preferably constructed in two mating partsso that their half round tubular portions It will be seen that, by thismeans, the illuminating means (the tubular lamps 35) are supported bythe longitudinal members 11 which in turn are suspended from thepermanent ceiling structure 24.

The cross members 12 are preferably in the form of T-bars as shown, eachcomprising an upright vertical portion 36 and a pair of outwardlyprojecting, horizontal coplanar flanges 37. A connector member isprovided for connecting each end of each T-bar 12 to a longitudinalmember 11, each such connector member having a head portion 38 which isreceived in the adjacent vertically aligned guideways 14, and a bodyportion terminating in a tip 39 which extends through a slot in theadjacent end of the respective T-bar. Further details regarding theconstruction and operation of the connector members will be found in ourPatent No. 2,888,113. Suffice it to say that other connection means maybe employed insofar as the present invention is concerned, but thatshown is preferred because, among other things, it permits connection toT-bars 12 to longitudinal members 11 at any point and it permits movingthe connected T-bars lengthwise of the longitudinal members 11 to anypoint desired. As explained in our Patent No. 2,888,113, the headportions 38 of the connector members are rounded at diagonally oppositecorners so that, by rotating them, they can be detached from andinserted in the guideways 14.

Light diffusing panels are shown at 40 which may be in the form of glassor plastic construction. They act to diffuse light from the tubularlamps 35 to provide a more diffused and more nearly homogeneous ceilingillumination. The panels 40 are supported by the flanges 37 of theT-bars 12 and also by the clips 9 on flanges 15 of the longitudinalmembers 11. In connection with FIG- URE 1 and elsewhere herein, where alight-transmitting panel or lens is shown or described, it will beunderstood that various types of light-transmitting members may be used.For example, clear, transparent glass or plastic may be used, which maytransmit light without modifying it. However, light-modifying panels andlenses are preferred, such as translucent glass or plastic, prismaticglass or plastic, egg crate or cellular louvres, etc., all of which havethe effect of diffusing and softening light and which are referred tocollectively herein as light-modifying members. It will also beunderstood that most of these light-transmitting members act also asreflectors, and as will become apparent in some embodiments of theinvention their light reflective quality may be of substantialimportance.

. The electrical system for the tubular lamps (e.g., fluorescent lamps)such as shown at 35 requires cross connections between the longitudinalmembers 11, which may be provided in the form of connector boxes 45 andpipes or tubes 46. Ballast are also provided as shown at 47 for thelighting system.

It will be apparent that the embodiment of the invention shown in FIGURE1 provides a combined, unitary, integrated lighting and ceiling systemwhich is suspended as a unit from a permanent roof structure such asthat shown at 24 and which has several important advantages among whichare the following:

The ceiling provides diffused ceiling illumination by reason of the factthat the tubular lamps 35 are supported above a translucent ceiling. Theentire structure can be suspended by the same means (the hanger members25, bolts 26 and wires, cables or rods 27) from a permanent ceiling andat any height desired. It is not necessary to suspend or support thelamps and their fixtures by one means and the ceiling by another means;nor is it necessary to hang the ceiling from the lamp fixtures.

The lamps 35 can be spaced apart independently of the module of theframework formed by the members 11 and 12, and the height of the lampsabove the panels 40 can be adjusted atwill by appropriate selection ofthe pedestals 29. The system can be suspended at any distance desiredbeneath the permanent ceiling 24.

The lamps 35 are shown transverse to the longitudinal members 11, whichhas as an advantage that the lamps can be spaced apart independently ofthe spacing of the frame members 11. However, as noted, this requirescross wiring means such as shown at 45, 46. In another embodiment of theinvention illustrated in FIG. 1A and which is suggested in both ouraforesaid Patents Nos. 2,888,113 and 3,085,152, the pedestals thereindesignated 2% can be turned 90 from the position of the correspondingprior described pedestals 29, by the platforms 33a thereof lengthened sothat they overhand the longitudinal members supporting the samesubstantially to provide outrigger arms, and the sockets 34a turned 90.from the position of the aforementioned sockets 34,

whereby to support the lamps 35 parallel to the longitudinal members 11but spaced outwardly so as to reduce shadow effects. This embodimentsimplifies wiring in that the cross wiring means 45, 46 is eliminated,but it does make the lamp spacing dependent upon the spacing of thelongitudinal members 11.

Referring now to FIGURE 2, another form of ceiling and lighting systemis there shown which is generally designated by the reference numeral60. It comprises longitudinal members 61 to which are connected'crossmembers in the form of T-bars 12 which are identical with the T-barssimilarly numbered in FIGURE 1 and which are connected to thelongitudinal members by similar means. Each of the longitudinal members61 comprises a raceway channel 62 having a function similar to theraceway channel 11a in FIGURE 1 (i.e., for wiring) although it is shapedsomewhat differently. It is equipped with cover plates 63. Thelongitudinal members 61 also provide a troifer or light reflector in theform of arcuate wings 6 1, one on each side of the channel member 62 andextending outwardly and downwardly. The two wings 64, together with theclosed bottom of the channel 62 provide a downwardly opening, upwardlyclosed light reflector and recess for tubular lamps.

Supported on the longitudinal member 61 by pedestals 29 are tubularlamps 35 as in the case of FIGURE 1. The suspension means is alsoidentical with that in FIG- URE 1, comprising hanger members such asshown at 25, bolts 26 and cables 27 suspended from a permanent ceiling(not shown). Translucent light diffusing panels 67 are provided whichare shown as being double thickness plastic members whose Walls 68 arespaced apart and whose edge portions 69 rest upon the flanges 37 of theT-bars 12 and flanges 61a of the longitudinal members 61. (As notedabove, other types of light transmitting, preferably light modifyingmembers, e.g., louvres may be used.)

Associated with each of the longitudinal members 61 is a light diffusingstructure generally designated by the reference numeral 70 which hasgrooved mounting portions 71 mating with complemental tongues 72 formedon the longitudinal member 61. A tongue and groove connection is thusprovided. Further details of this construction will be found in ouraforesaid Patent No. 2,956,150. Further description thereof isunnecessary for purposes of understanding the present invention. Alsoshown in FIGURE 2 is a T-shaped socket support bracket '73 to whichsockets 74 are attached. Tubular lamps 75 are supported by andelectrically connected to the sockets 74-.

Cross wiring conduits are provided one of which is shown at 76 and itcomprises a channel member '77 and a cover portion 78.

In connection with FIGURE 2 and other figures herein, it will beunderstood that a modular, grid-like framework is provided in whichlongitudinal and cross members, lamps, panels, etc. are repeated. Forsimplicity and brevity such repetition is not shown or is condensed inthe various drawings.

' It will be seen that the system shown in FIGURE 2 is generally similarto that shown in FIGURE 1. That is to say, it is an integrated ceilingand lighting system all Suspended as one unit from a permanent ceilingand having the feature of a luminous ceiling. However, it has the addedfeature of tubular. lamps at the ceiling level which provide rows orbands of more intense illumination. In such a system a more diffused,less intense illumination is provided by the above ceiling lamps 35 andtheir diffusers 67; a more intense, less dilfused band type ofillumination is provided by the ceiling level lamps 75 and their lenses70; and the two systems of lighting can be operated separately or theycan be operated together by energiZiu g both circuits. I

As in the case of FIGURE 1, the lamp 35 may be supported in parallelismto the longitudinal members 11.

Referring to FIGURE 3, a further embodiment of the invention is thereshown which is generally designated by the reference numeral 80. Itcomprises longitudinal members 11 suspended from a permanent ceilingstructure (not shown) by the same means as in FIGURES 1 and 2 (i.e., byhanger members 25, wires, cables or rods 26, etc.). Cross members areprovided in the form of T-bars 12 similar to the T-bars 12 shown inFIGURES'I and 2 and similarly connected to the sides of the longitudinalmembers 11. In this instance, however, the ceiling is intended to be anacoustical ceiling. To this end acoustical (i.e., sound-absorbing)panels 81 are provided which may be supported by resting on the flanges37 and but preferably they are slotted so as to provide a tongue andgroove connection. Cross wiring conduits are provided at 82. Theacoustical ceiling 81 also functions as a light reflecting ceiling. Ifonly light reflection is desired the panels 81 can be replaced bynonacoustical, light-reflecting material.

A further feature of the system shown in FIGURE 3 comprises an egg-crateor open louvre type of light diffuser shown at 83 which is suspendedfrom the longitudinal members 11, as by means of hangers 84 and rods 85.The rods 85 are welded or otherwise suitably secured to the louvre andthe hangers 84 and attached to the flanges 15 of the longitudinalmembers 11. Also shown are mounting brackets 86 bolted to theundersurfaces of the longitudinal members 11, such mounting brackets 86being similar to the pedestals 29 shown in FIGURES l and 2 but modifiedfor a suspension type of support rather than a pedestal type of support.To each of the brackets 86 is attached a socket 87 to which a tubularlamp 88 is connected. An upwmdly concave, downwardly convex lightdilfusing lens 89 is provided for 102 and rods 183 which are secured byany suitable means such as threading to the longitudinal members 184 ofthe ceiling framework 101. Each of the longitudinal members 184 has ingeneral the shape of an I-beam and it comprises vertically alignedguideways 105 which are similar to and have a function similar to thevertically aligned guideways 14 of the longitudinal members 11. shown inFIGURES 1 and 3. Also, each of the longitudinal members 104 has onopposite sides outwardly projecting coplanar flanges 106 which cooperatewith the flanges 37 of T-bars 12 to provide panel support means. Themeans connecting the ends of T-bars 12 to the longitudinal members 104is the same as that shown in FIGURES 1, 2 and 3. It will be seen thatthe framework mlprovides a grid in which the panel supporting flanges186 and 37 support light diffusing panels 187. The latter may be of anydesirable type but they are preferably double thickness, plastic panelslike those shown at 67 in FIGURE 2. v

The system shown in FIGURE 4 has in common with the system shown inFIGURES 1, 2 and 3, the advantages bodiment longitudinal members 11 areeach of the lamps 88. Each of the lenses 89 is supported by clips 90which are attached to the brackets 86.

Further description of the lenses 89 is unnecessary herein except tonote that they are preferably tapered in cross section so that they arethickest along their longitudinal axes in registry with the lamps 88 andare progressively thinner toward their edges, whereby a more even anddiffused type of illumination is provided. Further details concerningthis and related features will be found in our aforesaid Patent No.2,956,150.

In the system illustrated in FIGURE 3 an acoustical and/or lightreflecting ceiling is provided by reason of the acoustical tiles orpanels 81; a light diflusing ceiling is provided by virtue of the louvre83 assisted and augmerited by the lenses 89; and the entire assembly, asin the case of the systems of FIGURES 1 and 2, is sus pended as a unitfrom the permanent ceiling structure. In this case an integratedacoustical-light reflecting ceiling is suspended as a unit with the lampspacing and ceiling panels independent of each other. The lenses andlamps create a luminous indirect lighting effect.

Referring now to FIGURE 4 a further modification of the invention isthere shown comprising an integrated ceiling and lighting systemgenerally indicated by the reference numeral 180 and which compriseslongitudinal members 11 similar to those in FIGURES 1 and3 and which aresuspended from a permanent ceiling structure of being an integratedunitary ceiling and lighting system all suspended as one unit from apermanent ceiling structure. It can provide acoustical qualitiesinasmuch as the hollow, double thickness light diffusing panels 107function as acoustical members. ceiling providing a uniform ceilingillumination.

Referring now to FIGURE 8, yet another embodiment of the invention isthere illustrated which is generally designated by the reference numeral120. In this emprovided as in FIGURES 1, 3 and 4 to which are connectedcross members in the form of T-bars 12 as in the case of FIGURES 1, 3and 4. The longitudinal members 11 are suspended in like manner from apermanent ceiling structure (not shown). The coplanar supporting flanges15 and 37 support light transmitting members such as the louvre shown at121. Alternatively, plastic light diflusers may be employed or othersuitable light-transmitting means. It will be observed that, atintervals, adjacent T-bars 12 are located more closely together so; as toprovide a supportfor a light diffusing member such as shown at 122.'This may be a translucent glass lens or diffuser or a plastic lens ordiffuser. If desired, a lense 'such as that shown at 70 in FIGURE 2 maybe employed in which case the grooved connectors 71 will mate with theinwardly directed flanges 37 of the respective T-bars 12. Or a taperedlens such as shown at 89 in FIGURE 3 may be used. As will also beobserved,

sockets 123 are attached to the side walls of the longitudinal members11 to which tubular lamps 124 are connected above the light diffusingmembers 122. Each lamp is centered in relation to its lens 122.

Referring now to FIGURE 9, the ceiling and lighting system shown inFIGURE 8 is shown suspended from a permanent ceiling structure which inthis instance is preferably flat and uniform for purposes of uniformlight reflection. As will be seen a portion of the light from thetubular lamps 124 provides direct illumination downwardly through thelenses 122. Another portion of the light radiating from the lamps 124 isupwardly directed and it is reflected off the ceiling structure 24 anddown through the light diffusing panels 121.

It will be apparent that the embodiment of the invention shown inFIGURES 8 and 9 provides objects which are common to other embodimentsof the invention herein illustrated and described, that is to say, itprovides an The ceiling is a luminous integrated, unitary lighting andceiling system all suspended as a single unit from a permanent ceilingor roof structure. But in this instance all of the illuminationoriginates with lamps which are in the same plane as the framework ofthe ceiling, thereby leading to simplification.

Referring now to FIGURE 5, as noted above, it is frequently necessary toprovide conduits for cross connections electrically between the raceways11a of the longitudinal member 11. In FIGURE there is illustrated ameans whereby such cross conduits for cross wiring are provided and arecombined with cross members of the framework. As will be seen, T-bars131 are provided each having an upright plate portion 132 of relativelygreat height as compared to the T-bars 12 shown in FIGURES l to 4 anddescribed hereinabove. Bottom panel-supporting flanges 130 are providedwhich cooperate with the flanges 15 of the longitudinal members 11 tosupport panels as described hereinabove. Each of the cross members orT-bars 131 is of integral extruded construction'and includes at the topa channel member 133 integral with the upright plate portion 132.Guideways are provided at 132a to connect with T-bars (not shown)extending between the T-bars 131, as in our copending application SerialNo. 590,012, filed June 7, 1956, entilted Ceiling Framework. Connectormeans is provided to connect the ends of cross members 131 to thelongitudinal members 11, such connector means being the same as shown inFIGURES 1 to 4. A top cover 134 is provided which is snapped into thegrooved side walls of the channel and which has side wall portions 135for bridging the open top of the channels 11a. It will be apparent that,by this means, a simplified, unitary, integral means is provided forproviding cross members ofthe framework and cross conduits for thenecessary cross wiring of the lighting system.

Referring now to FIGURE 6 another type of cross conduit construction isthere shown comprising channel members 142. The ends of the channelmembers 142 are connected to the longitudinal members-11 by meansincluding L-shaped brackets 143 each of which is fixed to the bottomsurface of the respective channel 142 by means of a screw or rivet 144,and a clip 145. Each of the clips 145 has an upper lip 146 which gripsthe upper; surface of the bottom of the channel 142 and italso has alower lip 147which is received ina groove 148 formed in the adjacentside wall of the channel 11a of longitudinal member 11. (It will be seenthat the upper edge of eachside Wall of the channel or raceway 11a isformed with a pair of grooves 148and 149. The upper groove 149 serves tohold and to provide a snap connection with the cover portion.) A' coveris provided for each aligned pair of channels 142 in the form of amember 155 the edges of which at 156 are adaptedto snap over theoutwardly tapering edges of the channels 142. A bridging portion 157 isprovided which is secured to the cover 155 as by means of rivets 158.

Referring to FIGURE 7, an end of the cover'member 155 is there shownwhich is provided'with an end flap The constructions shown in FIGURES 5,6 and 7 provide convenient means for cross wiring of a tubular lightingsystem. Among their advantages may be mentioned the following: The formsshown in FIGURES 5 and 6 provide additional strength and rigidity to theceiling framework, particularly in the form shown in FIG- URES. Inaddition itwillbe apparent that the cross wiring can be connected at anypoint desired and, having been connected, it can be easilymoved alongthe longit3 tudinal members to any desired position. ,Itis a veryimportant advantage of the structure shown in FIG- URE 5, that itcombines into one integral extruded structure both a frame member forstructural strength and a cross channel for cross wiring.

It will, therefore, be apparent that a combined, integrated lighting andceiling system has been provided which provides a ceiling illuminatingsystem with or with out an acoustical means, such being all suspended asa single unit from a permanent ceiling or roof structurt? and beingeificient from the standpoint of illumination and, in the acousticalvariants, being also efficient for acoustical purposes.

We claim:

1. A luminous ceiling comprising a framework formed by spaced, parallellongitudinal members and cross members extending between and attached tosaid longitudinal members to form a substantially planar, grid-likestructure, said longitudinal and cross members being provided with panelsupport means to support ceiling panels substantially in the plane ofsaid grid-like structure; light transmitting ceiling panels engaging onand being sup ported by said panel support means; means directlysuspending said frame work from a permanent ceiling; tubularlampsdisposed intermediate said permanent ceiling and said ceiling panels inposition to illuminate substantially the entire expanse of said ceilingpanels by passage of light through said panels; means carried bysaidframework disposed above the ceiling panels and providing the solesupporting means for said lamps; and at least'certrain of said framemembers and said lamp supporting means forming conduit means havingwiring therein elec-. trically connected to the terminals of saidtubular lamps.

2. The luminous ceiling of claim 1 wherein said lamp- 9 supporting meanssupport said tubular lamps above the level of said framework.

3. The lighting and ceiling system of claim 2 wherein said lampsupporting means further support said tubular lamps in-spaced, parallelrelation with respect to the longitudinal members.

4. The luminous ceiling of claim 2 wherein said lamp supporting meanssupport said tubular lamps substantially in the plane of said framework.

5. The luminous ceiling of claim 1, wherein said lamp supporting meanssupport sa-id lamps above the longitudinal members of the framework; andwherein at least certain of said longitudinal members are in the. formof downwardly directed light reflectors, and additional tubular lampsare supported in said light reflectors and extend lengthwise thereofthereby to provide direct downward illumination in the form of bands ofillumination which extend between the adjacent panels which aresupported by said certain longitudinal members.

References Cited in the file of this patent UNITED STATES PATENTS2,041,965 Sargent May 26, 1936 2,306,685 Chambers Dec. 29, 19422,583,939 French et al. Jan. 29, 1952 2,616,533 Gannett et al Nov. 4,1952 2,734,126 Kruger Feb. 7, 1956 2,753,440 Wakefield July 3, 19562,884,512 'Wakefield Apr. 28, 1959 2,913,571 Smith Nov. 17, 19592,913,575 Lipscomb Nov. 17, 1959 2,926,237 Sorenson Feb. 23, 19602,939,543 Zingone June 7, 1960 2,946,413 Wiesmann July 26, 19602,951,147 Gilbert Aug. 30, 1960

1. A LUMINOUS CEILING COMPRISING A FRAMEWORK FORMED BY SPACED, PARALLELLONGITUDINAL MEMBERS AND CROSS MEMBERS EXTENDING BETWEEN AND ATTACHED TOSAID LONGITUDINAL MEMBERS TO FORM A SUBSTANTIALLY PLANAR, GRID-LIKESTRUCTURE, SAID LONGITUDINAL AND CROSS MEMBERS BEING PROVIDED WITH PANELSUPPORT MEANS TO SUPPORT CEILING PANELS SUBSTANTIALLY IN THE PLANE OFSAID GRID-LIKE STRUCTURE; LIGHT TRANSMITTING CEILING PANELS ENGAGING ONAND BEING SUPPORTED BY SAID PANEL SUPPORT MEANS; MEANS DIRECTLYSUSPENDING SAID FRAME WORK FROM A PERMANENT CEILING; TUBULAR LAMPSDISPOSED INTERMEDIATE SAID PERMANENT CEILING AND SAID CEILING PANELS INPOSITION TO ILLUMINATE SUBSTANTIALLY THE ENTIRE EXPANSE OF SAID CEILINGPANELS BY PASSAGE OF LIGHT THROUGH SAID PANELS; MEANS CARRIED BY SAIDFRAMEWORK DISPOSED ABOVE THE CEILING PANELS AND PROVIDING THE SOLESUPPORTING MEANS FOR SAID LAMPS; AND AT LEAST CERTAIN OF SAID FRAMEMEMBERS AND SAID LAMP SUPPORTING MEANS FORMING CONDUIT MEANS HAVINGWIRING THEREIN ELECTRICALLY CONNECTED TO THE TERMINALS OF SAID TUBULARLAMPS.